The US Nuclear Regulatory Commission began a week-long inspection at Florida Power & Light's Turkey Point plant Aug. 31 following three unplanned shutdowns at Turkey Point-3 that occurred in the second half of this month, NRC Region II spokesman Roger Hannah said.
Operators manually tripped 885-MW Turkey Point-3 in Homestead, Florida due to a "turbine runback" caused by a control valve failing to open, leading to a rise in steam generator water levels Aug. 17, FPL said in an event report filed to NRC. A runback means the turbine reduced load, FPL spokesman Peter Robbins said Aug. 18.
A lightning strike "is believed to be the initial cause of the runback," according to the event report.
The unit automatically tripped during startup Aug. 19 when an instrument sensed higher than expected neutron activity in the reactor core.
Operators manually tripped the reactor Aug. 20 when it was operating at about 35% of capacity "in response to the loss of the single operating steam generator feedwater pump," NRC said in a statement Aug. 31.
"The [inspection] team will review exactly what happened during each trip, how the operators responded, corrective actions the company has taken or plans to take, and how the company and operators may have applied training as well as any previous industry operating experience," Hannah said.
He noted, "It is too early to say what the inspection may reveal, but any apparent violations or other potential regulatory actions will be discussed in the inspection report which is expected to be issued within 45 days after the inspection is completed."
Robbins said Aug. 31, "We welcome this opportunity to share the details of equipment performance and the actions operators took to keep Turkey Point in a safe condition during the recent unplanned shutdowns. Turkey Point and FPL are always ready to fully cooperate with the independent experts at the Nuclear Regulatory Commission in the spirit of complete transparency."
Robbins added, "In all three cases, the reactor was shut down in a matter of seconds, and all safety systems responded as designed."
Turkey Point-3 synchronized to the grid Aug. 24 and was operating at full power Aug. 31, according to NRC's daily reactor status reports.
